That's the code. And, although my youngest is 19 and currently sitting his Leaving Certificate exams, he still adheres to it. It's part and parcel of family life and it's a rule that has solidly stood the test of time.

The call yesterday by television presenter Mary Berry for parents to lock away their children's mobile devices to force them to get outside and play with one another, makes good horse sense.

Despite Berry's advanced age - she's 81 - she has proposed an effective modern solution to an insidious modern problem.

The increasing ownership and usage of smartphones and other digital devices by young children - many of whom receive them as a First Communion or Christmas present - is a growing concern for parents who expect their kids to be active and outdoorsy.

"A lot of parents expect children to play in the same way that they did when they were younger, but tech has changed everything we do, including how our children play," explains psychologist Dr Jane Walsh, director of the m-Health Research Group at the University of Limerick - the group studies mobile technology and health behaviour.

Children need free, creative play, she says. They also require an element of boredom to foster their imagination and stimulate free play.

However nowadays, when kids get bored, they just start playing with devices. Concerned by how much time the children are spending on their screens, a parent may put the device out of reach, only to endure nagging complaints of boredom - and subsequently feel guilty.

However what such guilt-ridden parents need to know, says Walsh, a mother of five children between the ages of seven and 17, is that boredom is critical to encouraging a child to go out and enjoy free play, developing new games and getting involved in creative fund.

Berry said that she takes her five grandchildren's digital devices away from them during family holidays to encourage them to enjoy spending time together, and urged other families to do the same, telling Radio 4: "It is so brilliant to get all the young away from all those gadgets and tablets and things. Once you're out you forget that they even exist. Definitely they should be put away."

For Walsh, it is important that digital devices are not her children's default entertainment.

Her eldest three, aged 12, 15 and 17 all have phones, she says, but she is very conscious that their time on them is limited.

There are no devices in the bedrooms or at the dinner table, she says, and generally "minimal" use of devices is encouraged at other times.

She "automatically" takes devices and switches off phones and sends their young owners out to play, she says.

Her response to complaints of boredom, quips Walsh, is the same as that of her mother before her - she offers her children the choice of playing games out in the garden, or of coming inside to help her with the housework.

"Parents need to actively manage how children use devices and to take responsibility for their children's use of them," she says, observing that this is part of the "newer" challenges of modern day-to-day life.

For psychotherapist Stella O' Malley, author of 'Cotton Wool Kids', many modern parents allow children unfettered access to devices because it's a fail-safe way of keeping them quiet.

"It's not appropriate, but it's easier. Often it's not about parents being mindless but about being selfish and getting some peace," she says.

"It's easier for them to look the other way - in the same ways as it's easier to let a child eat a lot of junk food.

"Technology has its place, but remember, if you give sweets all the time to children they will be happy, but it's not good for them. The same goes for screen-time."

With two children aged six and eight, it's not her problem just yet, says Stella, however, she believes it's not always feasible to take devices off children and lock them away.

"This whole area is moving very fast - a few years ago, a lot of children under the age of 12 didn't have these devices, now many of them do.

"You cannot ban devices from children's lives completely," she says, adding that children who do not have the phones when their friends do, are losing out on a particular cultural context.

Managing their usage is not easy she warns - "you are drawing hassle on yourself by not allowing them to have complete free access to these devices" - but at the end of the day, she believes, that is our role as parents.

Parents must be the adult in the situation, believes Adele Flynn, principal of Edmund Rice College in Carrigaline, Co Cork.

"You have to look at the big picture. Parents should not allow any one activity to dominate a child's day - be that sports, homework or the use of a digital device," she says, adding that parents should ensure that a device does not become the focus of a child's day but refusing access to it in certain places such as the bedroom or at agreed times, when they are doing their homework or going to bed.

Remember, says psychotherapist Karl Melvin, allowing children free access to such devices will only encourage them not to participate in normal family interaction.

"They're not listening to each other or to parents because they're always on their phone," says Melvin, the author of toxicscape.com, who works with parents who experience difficulties with their children.

"Parents have to manage it and they will have to step up and take responsibility.

"There should be agreed designated times for use - and at other times the phone should be put away," he says.

Parental control, guidance and house rules around digital media must be established, emphasises Laura Haugh of Mummypages.ie.

"Your child's access to a smartphone should be considered a privilege that can be taken away if abused, for example, texting when they should be doing their homework."

Melvin agrees: "Parents have to make the call and agree limits in terms of homework, family meals and social events - it's about teaching healthy behaviour around the mobile phone.

"There are children out there and all they know is tech and digital media. This is about them talking to other people and paying attention to things, and part of that involves disconnecting so that they are not always on a digital device."